Detection of carotid intima and media thicknesses based on ultrasound B-mode images clustered with Gaussian mixture model / 生物医学工程学杂志

In clinic, intima and media thickness are the main indicators for evaluating the development of atherosclerosis. At present, these indicators are measured by professional doctors manually marking the boundaries of the inner and media on B-mode images, which is complicated, time-consuming and affected by many artificial factors. A grayscale threshold method based on Gaussian Mixture Model (GMM) clustering is therefore proposed to detect the intima and media thickness in carotid arteries from B-mode images in this paper. Firstly, the B-mode images are clustered based on the GMM, and the boundary between the intima and media of the vessel wall is then detected by the gray threshold method, and finally the thickness of the two is measured. Compared with the measurement technique using the gray threshold method directly, the clustering of B-mode images of carotid artery solves the problem of gray boundary blurring of inner and middle membrane, thereby improving the stability and detection accuracy of the gray threshold method. In the clinical trials of 120 healthy carotid arteries, means of 4 manual measurements obtained by two experts are used as reference values. Experimental results show that the normalized root mean square errors (NRMSEs) of the estimated intima and media thickness after GMM clustering were 0.104 7 ± 0.076 2 and 0.097 4 ± 0.068 3, respectively. Compared with the results of the direct gray threshold estimation, means of NRMSEs are reduced by 19.6% and 22.4%, respectively, which indicates that the proposed method has higher measurement accuracy. The standard deviations are reduced by 17.0% and 21.7%, respectively, which indicates that the proposed method has better stability. In summary, this method is helpful for early diagnosis and monitoring of vascular diseases, such as atherosclerosis.

The experimental study of cell density mediated integrin αγβ6 expression and MMP-9 secretion in colon cancer cells / 中华普通外科杂志

Objective To detect the effect of cell density off both integrin αγβ6 expression and matrix metalloproteinase-9(MMP-9)secretion in colon cancer cells. Methods Flow cytometry was applied to analyze αγβ6 expression in human WiDr colon cancer cell lines and human HaCaT keratinocyte cells, respectively,at high-and low-cell density culture.The MMP-9 aetivity level for various coloIl cancer cell lines, WiDr and SW480 cells at high-and low-cell density culture was analyzed using Biotrak MMP-9 activity assay and Gelatin Zymography assay, respectively. Results High cell density significantly enhances integrin αγβ6 expression for WiDr cells expressing αγβ6 compared with low density,but no increase was observed for human keratinocyte HaCaT cells. Biotrak MMP-9 assay indicated that the amount of MMP-9 secreted per cell for WiDr and SW480 B6 cells at high cell density culture was(3.3±1.2)×10-7ng/cell and(27.2±3.0)× 10-7ng/cell respectively; However,at low cell density it was(1.8±0.7)× 10-7ng/cell and(10.9±2.0)×10-7 ng/cell,respectively. It was 2-3-fold higher for WiDr and SW480 β6 cells at high cell density compared with that at low cell density, but no density-dependent increase observed for SW480 wild cells lack αγβ6 expression(t=0.47,P＞0.05),MMP-9 secretion for SW480 wild cells was(3.9±1.7)× 10-7 ng/cell at hish cell density and(3.8 ±0.7)×10-7 ng/cell at low eell density(P＞0.05),respectively. Gelatin zymography assay also indicated that the level of MMP-9 in SW480 B6 cells expressing αγβ6 was evidently higher at high density than at low density, however no density-dependent increase observed for SW480 wild cells and HaCaT cells. Conclusions High cell density induces integrin αγβ6 expression and promotes MMP-9 secretion in colon cancer cells, which constitutes the basis for a self-perpetuating system of tumor infiltrating growth in colon cancer progression.

Analysis of the Utilization of Chinese Traditional Medicines in Our Hospital / 中国药房

OBJECTIVE:To evaluate the status quo of the application of Chinese traditional medicines andthe problemslie in the development of the application of Chinese traditional medicine.METHODS:The Chinese traditional medicines used in outpatients from Apr.2006to Apr.2007in our patient were analyzed statistically in respect of the consumption sum,con-sumption quantity and drug category.RESULTS:Leading the list in terms of consumption quantity in the outpatient depart-ment were heat-clearing drugs,detoxicating drugs,dampness-drying drugs and haemostatics.The utilization of Chinese traditional medicines in outpatients was standard on the whole,but there were still some irrational phenomena.CONCLU-SION:To enhance the curative efficacy of Chinese traditional medicines and standardize their use,the co-effort of both hospital staff and the society is much needed.